From one day to another Chrome is suddenly behaving different about the Bootstrap class .bs-gradient It randomly changes the gradient to color breaks of black, lightblue, darkblue and so on:
Here's the Code of one of those Boxes:
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.0/dist/css/bootstrap.min.css" integrity="sha384-KyZXEAg3QhqLMpG8r+8fhAXLRk2vvoC2f3B09zVXn8CA5QIVfZOJ3BCsw2P0p/We" crossorigin="anonymous">
<div class="col clickable">
<div class="click_left"></div>
<div class="click_right"></div>
<div class="card bg-primary bg-gradient">
<div class="card-body">
<div class="stock_item">
<div class="stock_name row">
<div class="col">
T-Shirt Motiv Zirkuskind Blau 140
</div>
</div>
<div class="stock_qty row">
<div class="col-4">
<button type="button" class="btn btn-danger">
<i class="bi bi-dash-lg"></i>
</button>
</div>
<div class="col-4 qtydiv">
<div class="qtyfield" data-id="">
10
</div>
</div>
<div class="col-4">
<button type="button" class="btn btn-success">
<i class="bi bi-plus-lg"></i>
</button>
</div>
</div>
</div>
</div>
</div>
</div>
With other Browsers and even on my phone with chrome it works completely normal.
These are the properties that Bootstrap 5 gives to the classes "bs-primary", "bs-gradient" and "card":

